The long-range purpose of the project is to study the biochemistry, morphology, pharmacology and physiology of synaptic transmission and neuronal connections of nerve cells of the mammalian cochlear nucleus. The interest is now focused on: 1) the application and further development of a system of computer programs for storing and displaying information on the localization, synaptic connections and activity of cells in the cochlear nucleus and for controlling experiments and processing results; 2) the decrease of aspartic acid and glutamic acid in the cochlear nucleus following cochlear ablation and in waltzing guinea pigs, indicating that aspartic acid or both amino acids may serve as transmitter(s) of the auditory nerve; 3) the ultrastructural changes at auditory nerve synapses in the cochlear nucleus, as seen using freeze-fracture techniques, with activity, with degeneration in waltzing guinea pigs, with degeneration following cochlear ablation; 4) the connections of the cochlear nucleus, using horseradish peroxidase labeling and other techniques for defining neurons and a computer based system for locating cells on microscopic slides. BIBLIOGRAPHIC REFERENCES: Adams, J. C.: Technical considerations on the use of horseradish peroxidase as a neuronal marker. Neuroscience 2: 141-145, 1977.